Monday, April 27, 2009

A Wh(ITER) elephant?

Imagine a machine that you can throw in a few grams of hydrogen – which abounds in the Earth’s oceans – crank it a few times, and harvest massive amounts of cheap energy. And all that thanks to fusion, a physical process where the nuclei of two elements (for example deuterium and tritium, which are kinds of hydrogen) fuse together to produce a new element (helium). The new, fused, nucleus is somewhat less than the sum of the two original nuclei, and the residual mass becomes energy (called “thermonuclear”) according to Einstein’s famous formula E=mc2. And that’s all the physics you need to solve Earth’s energy problems!

Fusion sounds too good - and because it is also true - it has led to ITER, the “International Thermonuclear Experimental Reactor”, a 10billion dollar megaproject, jointly funded by the EU, Russia, US, Japan, South Korea, China and India. ITER’s long and turbulent history began in 1985 as a political-cum-scientific gesture towards easing Cold War tensions. The West and the Soviet Union, each one having developed their own thermonuclear technologies, decided to put them together for the benefit of all mankind. The Soviet Union collapsed but ITER survived. After much politicking and dramatic bargaining over the ensuing decades, its location has been finally decided: Cadarache, near Marseille.

ITER will take 10 years to construct, and 20 more years to operate. It will build upon experience gained from previous experiments, such as JET (The “Joint European Taurus”), and will test new ideas and designs for a reactor. Although the science is well-known and straight-forward, the engineering is a daunting task evermore. For nuclear fusion to occur elements have to be stripped off their electrons. This state of “electron-less” matter is called “plasma”. The Sun is a fireball of plasma and its radiant energy is theorized to be the result of naturally occurring fusion. Plasma only exists in extremely high temperatures and therefore no material container can contain it. So engineers must develop something “immaterial”; a magnetic field powerful enough to hold plasma at 100 million degrees centigrade. By 2018 the hope to fuse half a gram of hydrogen, sustain the generated plasma for 400 seconds, and produce 500MW of energy. (By comparison, in 1997 JET managed to sustain plasma for half a second only and produce 16.1MW). Commercial thermonuclear reactors are envisaged by 2050.

The promise of ITER is environmentally benign, widely applicable, essentially inexhaustible electricity. Criticism from environmental groups focuses mainly on safety and waste disposal; however safety is inherent in fusion reactors (if plasma cools, even slightly, reactions stop at once) and the only waste is water. Fusion reactors may become radioactive but much less so than commercial nuclear reactors currently in use; and tested technologies to safely manage decommissioning already exist. Indeed, faced with the huge challenge to drastically cut down on greenhouse emissions, thermonuclear energy seems god-sent. Economic growth, which lifts people out of poverty, increases prosperity and guarantees peace, is based on the assumption of cheap, renewable, and widely available, energy resources. Such resources do not exist on our planet. Solar, wind and hyrdo cannot keep pace with the required rates of economic growth. Thermonuclear, with its zero emissions, inherent safety, minimum waste management overheads, and Mega-watt energy output is seen, by ITER’s supporters, as the only real alternative.

Nevertheless, serious scientific skepticism points to the fact that, although the uranium-fission bomb that obliterated Hiroshima and Nagasaki in 1945 has found peaceful use in nuclear reactors, the hydrogen-fusion bomb of 1952 has not. Containing the plasma at 100 million degrees for any economically meaningful period, may be an impossible engineering feat. Furthermore, the prevailing theory that the Sun is a gigantic fusion reactor is currently in dispute because it does not comply with new measurements of solar radiation. NASA is scheduling missions to investigate alternative explanations for the Sun’s mysterious energy cycle.Could ITER be a White Elephant? A multi-billion megaproject which will result in nothing but water?Questions such as these have led the US to vacillate in and out of ITER, and Canada to let go for good. The current political climate does not help either. The reasoning behind any “blue-sky” exploration smacks against the “precautionary principle”, an idea dominating contemporary political discourse. In a risk-averse society, playing with an expensive toy full of radioactive plasma may sound like an abomination. And yet we humans have managed to survive thus far by taking risks, by going out there and hoping to discover something new. Stifling potentially vital innovation on the grounds that it is “very difficult” to produce any results, or that it may incur “risk”, may be a far more dangerous proposition.